Chuck



Ab il 7, 1925 H. R. MCCONNEL CHUCK Original Filed Sept. 30, 1922 gnvenl'oz mm Patented Apr. 7, 1925.

HEB, stares HARRY E. BICCOI-INELL OF RIGHIJIOND, VIRGINIA, ASSIGLIOR TO THE MOGONNELL- BBOVTNING ENGINEERING: QQMEANY, 0F BIGHMOND, VIRGINIA, A CORPORATION OF VIRGINIA.

CHUCK.

Application filed September 30, 1922, Serial No. 591,536. Renewed August 16, 1924.

To all whom it may concern.-

Be it known that I, HARRY R. MoCoNNnLL, a citizen of the United States residing in the city of Richmond and State of Virginia, have invented certain new and useful Improvements in Chucks of which the following is a specification.

This invention relates to chucks and more particularly to such a device provided with gripping elements adapted to be clamped about the shank of a tool and having actuating means whereby the gripping element may be easily and rapidly advanced into loose engagement with the tool. mentary means being provided for tightly clamping the gripping elements about the tool.

In the chucks now commonly employed, there is provided a plurality of gripping elements having arcuate threads formed in their outer faces engaged by an internally threaded rotatable sleeve whereby they may be moved into engagement with the shank of a tool. If the threads employed are of slight pitch so that the tool may be tightly gripped with little likelihood of becoming loose during the operation of the chuc it requires a number of turns of the sleeve to move the gripping elements a relatively short distance with a consequent loss of time. It is the usual practice therefore to provide relatively high pitch threads whereby the gripping elements may be quickly moved to the engaging position, but the use of such a construction results in the frequent loosening of the gripping elements.

It is an important object of the present invention to provide gripping elements and a rotatable sleeve having relatively high pitch coacting threads whereby the gripping elements may be rapidly advanced into loose engagement with the tool. and to provide cooperating means to tightly clamp the gripping elements about the tool. said last named means being of peculiar construction whereby it may be efliciently operated by hand without the use of a wrench or other tool.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the drawings, I have shown one embodiment of the invention. In this shows c Figure 1 is a side elevation of a chuck embodying the invention supple Figure 2 is a central longitudinal sectional view taken substantially on line 2-2 of Figure 5,

Figure 3 is a detail view of one of the clamping elements,

Figure at is a side elevation of the body portion of the device showing the slidable sleeve in place thereon,"

Figure 5 is a section on line 5-5 of Figure 2, and,

Figure 6 is a similar view on line 66 of Figure 2.

Referring to the drawings,.the numeral 10 designates, as a whole, the body portion of the chuck mounted upon a rotating sp'indle 11 driven by a drill press or other machine. The body portion 10 is provided with a plurality of downwardly converging openings 12 in which are mounted slidable gripping elements 13 having tool engaging portions 14 adjacent their lower ends. The

gripping elements are provided with reduced upper ends 15 having screw-threads 16 of relatively high pitch formed on the outer faces thereof. The body portion is provided intermediate its ends with an annular groove 17 communicating with the openings 12. ring 18 is rotatably mounted in the groove 17 and, as shown in Figure 2, this ring is of slightly less width than that of the groove 17. The ring 18 is internally threaded as at 19 to engage the threads 16 of the gripping elements. The ring 18 is split as at 18' to permit it to he slipped over the lower end of the body portion 10 when assembling. A sleeve 20 is mounted upon the ring 19, having a driving fit therewith whereby rotation of the sleeve 20 will rotate the ring 18.

A sleeve 21 surrounds the body portion above the ring 18 and sleeve 20 and contacts the upper face of the ring 18 as shown. The sleeve 21 is movable longitudinally of the body portion but is fixed against rotational movement by a key 22 carried by the body portion 10 as shown in Figure 5. The outer surface of the sleeve 21 is threaded as at 23. These threads are preferably right hand threads pitched at 16 to the inch. The portion of the body portion extending above the sleeve 21 is externally screw-threaded as at 24, the threads being right hand threads to correspond with the threads 23 but are preferablypitched at 15 to the inch.

As clearly shown in Figure 2, a sleeve 25 surrounds the sleeve 21 and the upper end of the body portion 10. The upper end of the sleeve 25 is provided with internal threads adapted to engage the threads 24 while the lower end thereof is provided with internal threads adapted to engage the threads 28 of the sleeve 21.

The operation of the device is as follows:

The gripping members 13 are withdrawn upwardly by rotation of the sleeve 20 and the shank of the tool inserted as will. be obvious. The sleeve 20 is then rotated in the reverse direction until the gripping portions 14 contact with the shank of the tool. The sleeve 25 is then rotated in a clockwise direction looking from the top of the device. As stated, the threads 21 are preferably arranged at a pitch of 15 threads to the inch while the threads 23 are arranged on a pitch of 16 threads to the inch. Thus it will be obvious that one complete revolution of the sleeve 25 will move it downwardly upon the body portion 10 a distance of 1/15 of an inch. Since rotation of the sleeve 21 is prevented by the key it will be seen that a single revolution of the sleeve 25 will cause the sleeve 21 to move upwardly 1/16 of an inch with respect to the sleeve 25. However the sleeve 25, under such movement, has moved downwardly 1/15 of an inch, hence it will be seen that the sleeve 21 will move downwardly with respect to the body portion a distance equal to 1/15 of an inch minus 1/16 of an inch, or .0041 of an inch by actual measurement. While I prefer to employ threads having pitches as above described, it will be obvious that other pitches may be employed, the threads 23 and 2 1, however, both being either right or left hand threads, in which latter case the sleeve 25 would be rotated in the opposite direction to move the sleeve 21 downwardly with respect to the body portion 10. When the sleeve 25 is rotated, as above described, to accomplish the downward movement of the sleeve 21, the latter, contacting with the upper face of the ring 18, will move the latter downwardly whereby the gripping members 13 will tightly engage the shank of the tool. It will be obvious that the construction and operation herein described permits of considerable leverage between the rotational movement of the sleeve 25 and the sliding movement of the sleeve 21. Thus it has been found that a. very eflicient gripping action upon the shank of the tool may be obtained by manual operation of the sleeve 25 without the use of a wrench or other tool, and at the same time rapidity of action is obtained by the high pitch of the threads 16 and 19 whereby the gripping jaws are quickly brought into contact with the shank of the tool before the sleeve 25 is rotated,

It is to be understood that the form of my invention herewith shown and described is to be taken as apreferred example of the same and that various changes in the shape, size, and arrangement of parts may be resorted to without departing. from the spirit of the invention orthe scope of the subjoined claim.

Having described my invention, I claim:

A chuck comprising a body portion having its upper end threaded, a plurality of downwardly converging slidable gripping elements carried by said body portion and adapted to be clamped about a tool, said gripping elements being provided upon their outer faces with relatively high pitch threads, a rotatable ring surrounding said body portion and having internal threats engaging the threads on said gripping elements, an externally threaded slidable sleeve surrounding said body portion between said rotatable ring and the threaded end of the body portion, said rotatable ring being capable of relatively slight longitudinal movement limited in one direction by said slidable sleeve, the threads on said body portion and said sleeve being of different pitch, and a rotatable sleeve surrounding said body portion and having internal threads engaging the threads on said slidable sleeve and said body portion.

In testimony whereof I affix my signature in presence of two witnesses;

HARRY R'. MCGONNELL. lVitnesses R. H. HAMMELL, GHAs. A. CLARK. 

